Implantable medical devices are often provided with a fixation member for maintaining the device at a desired location within a patient's body. For example, elongated medical devices such as catheters and electrical leads may include a fixation member at or near the distal end of the device for maintaining the position of the device at a targeted implant site. Fixation members can include active and/or passive fixation members, for example in the form of hooks, barbs, helices or tines.
Implantable medical leads are used for deploying electrodes or physiological sensors to a targeted implant site. The lead carries electrical conductors allowing electrical connection of the deployed electrodes or sensors to a medical device such as a pacemaker, implantable cardioverter defibrillator, neurostimulator, or physiological monitor. Fluid delivery catheters may be used for delivering a fluid to a targeted body site to achieve an optimal effect. Fluid delivery catheters are generally coupled to a pump or other fluid dispensing device. A fluid delivered to a targeted site may be a dye used in a monitoring or diagnostic procedure, or a pharmaceutical agent or genetic or biological material for achieving a therapeutic effect. Reliable monitoring and/or therapy delivery by an implanted medical device is typically dependent on proper and stable positioning of the medical device. As such, many medical devices require a fixation member that reliably maintains the position of the device at a targeted body site without causing significant tissue trauma. In some cases, a delivery tool is needed for deploying the device to the targeted site.
Depending upon the nature of the medical device, fixation may be permanent or temporary. Thus, the fixation mechanisms is selected accordingly. For example, a cardiac pacing/defibrillation lead is implanted for long term use and the fixation mechanism may be rather robust, such as a helical member screwed into tissue. Conversely, many catheters are inserted on a temporary basis. Thus, while important to secure these device in place as needed; it is also important to be able to remove and retract these devices from the human body without adverse consequence.